Class-D switching audio amplifiers can employ a continuous-time, sigma-delta type architecture in the modulator block. For example, instead of a simple cascaded gain stage fed into a slicer/comparator together with a high frequency ramp signal (>10× the highest frequency in the baseband), integrators can be employed to achieve a shaped transfer characteristic having very high gain in the baseband region, and therefore low distortion. The integrators can also be employed to drive switching noise to frequencies well outside of the band of interest. The overall loop can be closed by acquiring the feedback signal directly from the output terminals for introduction into the summing nodes of the integrators. However, in many applications—such as battery-operated systems—the power supply voltage at the output stage can vary over as much as a 2:1 operating range. This produces a corresponding variation in the energy fed back into the integrators that can negatively influence modulator stability, as well as give rise to artifacts such as bimodal modulation.